Supersensitized photographic emulsions containing sulfonated compounds



SUPERSENSIT IZEID PHOTOGRAPHIC EMULSIONS CONTAINING SULFONATED COMPOUNDS Filed March 30, 1956 Fig.1

H m FFH ZIIW ml mm ""h-l||l 300 400 500 600 r 700 A= 35: DIETHYLOXATHIADICARBOCYANiNE IODIDE B= 3,3 DIETHYLOXATHIADICARBOCYANINE IODIDE PLUS 3,7- BIS (B- TOLYLAMI DO) "2,B'DISULFODIBENZOTH|OPHENE"5,5'DIOXIDE SODIUM SALT E392 fell!) in; IL LNI m1 mm 31H m 300 400 500 600 700 C= 3,3" DIETHYLOXATHIADICARBOCYANINE IODIDE 0 3,3"DlETHYLOXATHIADICARBOCYANINE IODIDE PLUS 3,7 BIS (4- METHYL'Z METHOXYBENZAMIDOY'Z ,SDISULFODIBENZOTHIOPHENE 5,5 DIOXIDE SODIUM SALT 500 600 700 E=3,3'- DIETHYIJHIADICARBOCYANINE IODIDE F= 3,3" DIETHYL HIADIGARBOCYANINE IODIDE PLUS 3[4(4' METHOXY3 SULFOBENZAMIDO) PHENYLJ'?(4'METHOXY3'SULFOBENZ AMIDO) DIBENZOTHIOPHENE'5,5'DIOXIDE SODIUM SALT John Spence JamesA.Van Allan Jean E. Jones dwmzvaea United States Patent SUPERSENSITIZED PHOTOGRAPHIC EMULSIONS CONTAINING SULFONATED COMPOUNDS Jean E. Jones, John Spence, and James A. Van Allan,

Rochester, N.Y., assignors to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey This invention relates to photographic emulsions containing dicarbocyanine dyes, and in supersensitizing combination therewith, certain sulfonated compounds.

It is known in the art of making photographic emulsions that certain dyes of the cyanine class alter the sensitivity of photographic emulsions of the gelatino silver-halide kind, when the dyes are incorporated in the emulsions. It is also known that the sensitization produced by a given dye varies somewhat with the type of emulsion in which the dye is incorporated. Furthermore, the sensitization of a given emulsion by a given dye may be altered by varying the conditions in the emulsion. For example, the sensitization may be increased by increasing the silver ion concentration or decreasing the hydrogen ion concentration (i.e., increasing the alkalinity) or both. Thus, sensitization can be increased by bathing plates, coated with a spectrally sensitized emulsion, in water or in aqueous solutions of ammonia. Such a process of altering the sensitivity of a sensitized emulsion by increasing the silver ion concentration and/or by decreasing the hydrogen ion concentration is commonly called hypersensitization." Hypersensitized emulsions have generally poor keeping qualities.

We have now found another means of altering the sensitivity in emulsions containing dicarbocyanine dyes. Since the conditions in the emulsion, i.e., the hydrogen ion and/or the silver ion concentration undergo little or no change in our method, we shall designate our method as a kind of supersensitization.

It is, therefore, an object of our invention to provide photographic emulsions containing dicarbocyanine dyes and, in supersensitizing combination therewith, certain sulfonated compounds. Another object is to provide photographic emulsions which are especially useful in color photography. Still another object is to provide methods for making these emulsions. Other objects will become apparent from a consideration of the following description and examples.

The dicarbocyanine dyes which are useful in practicing our invention include, for example, those represented by the following general formula:

wherein R and R each represents an alkyl group, such as methyl, ethyl, B-hydroxyethyl, carboxymethyl, B-carboxyethyl, carbomethoxymethyl, carbethoxymethyl, etc., It represents a positive integer of from 1 m2, X represents an acid radical, such as chloride, iodide, bromide, perchlorate, p toluenesulfonate, benzenesulfonate, ethylsulfate, methylsulfate, etc., Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus containing from 5 to 6 atoms in the heterocyclic ring, e.g., a heterocyclic nucleus of the benzothiazole series (e.g., benzothiazole, 4-chlorobenzothiazole, S-chlorobenzothiazole, 6-chlorobenzothiazole, 7-chlorobenzothiazole, 4-methylbenzothiazole, S-methylbenzothiazole, 6-methylbenzothiazole, S-bromobenzothiazole, 6-bromobenzo thiazole, 4-phenylbenzothiazole, S-phenylbenZothiazole, 4 methoxybenzothiazole, 5 methoxybenzothiazole, 6- methoxybenzothiazole, 6-iodobenzothiazole, S-iodobenzdthiazole, 4-ethoxybenzothiazole, S-ethoxybenzothiazole, 5,6 dimethylbenzothiazole, 5 hydroxybenzothiazole, 6- hydroxybenzothiazole, etc.), a heterocyclic nucleus of the naphthothiazole series (e.g., tit-naphthothiazole, ft-naphthothiazole, 7-methoxy-a-naphthothiazole, B-methoXy-anaphthothiazole, 5-methoxy-jS-naphthothiazole, S-ethoxytat-naphthothiazole, etc.), a heterocyclic nucleus of the benzoselenazole series (e.g., benzoselenazole, S-chlorobenzoselenazole, 6 methoxybenzoselenazole, 5 methoxybenzoselenazole, etc.), a heterocyclic nucleus of the naphthoselenazole series (e.g., (ac-naphthoselenazole, pnaphthoselenazole, etc.), a heterocyclic nucleus of the benzoxazole series (e.g., benzoxazole, S-hydroxybenzoxazole, 6 hyd-roxybenzoxazole, 5 chlorobenzoxazole, 5- methoxybenzoxazole, 6-methoxybenzoxazole, S-phenylbenzoxazole, S-bromobenzoxazole, etc.), a heterocyclic nucleus of the naphthoxazole series (e.g., a-naphthoxazole, B-naphthoxazole, etc.), a heterocyclic nucleus of the Z-quinoline series (e.g., Z-quinoline, 6-methyl-2- quinoline, 7-methyl-2'quinoline, 8-methyl-2-quinoline, 6- chloro 2 quinoline, 8 chloro-2-quinoline, 4 chloro 2- quinoline, S-ethoxy-2-quinoline, 6-ethoxy-2-quinoline, 7- ethoxy-Z-quinoline, 6-hydroxy-2-quinoline, 7-hydroxy-2- quinoline, 6-methoxy-2-quinoline, etc.) a heterocyclic nu! cleus of the 4-quinoline series (e.g., 4-quinoline, 6-methoxy-4-quinoline, 7-methyl-4-quinoline, 8-methyl-4-quinoline etc.), a heterocyclic nucleus of the benzimidazole series (e.g., benzimidazole, 5-chlorobenzimidazole, 5,6- dichlorobenzimidazole, 1,7 trimethylenebenzimidazole, etc.), and a heterocyclic nucleus of the 5,6-benzoquino line series (e.g., 5,6-benzo-2-quinoline, etc.), etc., and 2 represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzoxazole series (e.g., such as those defined by Z above), those of the naphthoxazole series (e.g., such as those defined by Z above), those of the benzoselenazole series (e.g., such as those defined by Z above), those of the naphthoselenazole series (e.g., such as those defined by Z above), those of the benzothiazole series (e.g., such as those defined by Z above), those of the naphthothiazole series (e.g., such as those defined by Z above), etc.

The sulfonated derivatives useful in practicing our invention comprise polycyclic aromatic sulfonic acids, or salts thereof, and dibenzothiophene dioxide compounds containing at least one sulfonic acid group, or salts thereof. The term polycyclic aromatic as used herein is intended to mean two or more benzene rings fused together (for example, as in naphthalene, pyrene, etc.) or at least two benzene rings directly joined together (for example, as in diphenyl, terphenyls, etc.). By dibenzothiophene dioxide we mean the ring system:

Of course, both the dibenzothiophene dioxide and polycyclic aromatic compounds contain at least one sulfonic acid group, or a salt thereof. Particularly useful polycyclic aromatic compounds contain from 12 to 30 carbon atoms. Particularly useful dibenzothiophene compounds containing at least one sulfo group (or salt) include those represented by the following general formula:

CHaO

described in the art. Such methods are illustrated in the copending applications of B. H. Carroll et al. Serial Nos. 540,052 4, filed October 12, 1955 (Serial No. 540,053, issued as Patent No. 2,875,058, on February 24, 1959).

The dibenzothiophene dioxide compounds useful in practicing our invention can be prepared in a manner illustrated below. Compounds wherein R and R represent an acylamido group can be prepared as described in US. Patents 2,573,652 and 2,580,234. See also US. Patent 2,563,493, issued August 7, 1951.

The sulfo-nated derivatives which can advantageously be used in practicing our invention include those represented by the following formulas:

N303 SOaNa 20 3,7-diacetamido-2,8-disu1f0dibeirzothiophene dioxide sodium i NH-C-QOCHa S OsNB S OaNa 3,7 -bls (4-methoxy-3-sulfobennamido) dibenzothlophene dioxide 3,7-bis (Z-ethoxybenzamldo) -2,S-disulfodibenzothiophene dioxide sodium salt 3 -NH NH-C- oorrr OC H; NaOzS soaNa OCzHg,

3,7-bis (2,4-diethoxybenzamido -2,8-disulfodibenzothiophene dioxide sodium salt NaOaS SOaNa 3-(4-sulfophenyl)-7-snlfodibenzothiophene dioxide sodium salt s mmsfl @Qwonn 3-(4-su]fobiphenylyl)-7-snlfodibenzothiophene dioxide sodium salt 0 II S NaOzs SO3Na 3,7-bis (p-tolylamido -2,8-disulfodibenzothiophene dioxide sodium salt (20) sensitivity conferred upon an emulsion by a sensitizing dye does not increase proportionately to the concentration of some the dye in the emulsion, but rather passes through a maximum 'as the concentration is increased. In practicing our invention, the dicarbocyanine dyes are advantageously employed in a concentration approximating their optimum concentration (i.e., the concentration at which the dye gives greatest sensitivity), In general, the sulfonated derivatives employed in our invention have little or no sensitizing action in the emulsions employed. 5,9-dlsulfo-7,12-dithiainde5o[1,2-afluorene-7,12-blsdloxide The ptimum concentration of an individual sensitiz- (21) Sa ing dye can be determined in a manner well known to NBCS SONB those skilled in the art by measuring the sensitivity of a series of test portions of the same emulsion, each portion containing a difierentportion of the sensitizing dye. The p Terpheny1 4,,4,,2 msulfonic new sodium salt optimum concentration of the dicarbocyamne dyes (22) OCH, OCH;

I (I: l

SOSNS a 4',4 -bis (2-methoxy-5-suliolgg31gamldo)-p-terphenyl sodium (23) OC H; OCaHn I O Q-C-NH NH- C a SOaNa SOaNa 4:,4"-bis(2-ethoxy-5-sulfobenzamldo)-p-terphenyl sodium salt (24) used in our invention can, of course, be readily determined in the same manner by measuring the senll sitivity of a series of test portions of the emulsion, each 0031 portion containing a different concentration of the dicarbocyanine dye to be used in the combination. In de- I Some 5 termining the optimum concentration for the supersensitizing combination, it is advantageous to employ at first Pyrene 3 methoxy a sulfostyryl)ketone sodium salt a concentration of the dicarbocyanine dye less than its l O CH: O CH:

4',4"-bls(2-methoxy-5-sulfobenzmnldo)-p-terphenyl (used as trlethanolamine salt) 80 E: 80:15 I (I? (I? I OCaHs 602E:

4Z4"-bis(2-ethoxy-fi-sulfobenzamido)-p-terphenyl (used as triethanolamine salt) As can be seen above, many of th lf t d d i optimum concentration, and then gradually increase the ti eS are employed in the form f th i w t l bl concentration of the dicarbocyanine dye until its optimum salts, such as alkali metal (e.g., sodium, potassium, etc.) concentration is determinedsalts, or ammonium or amine (e.g., triethylamine, tri- Ordinarily, the Optimum heal p'q eh ethanolamine, pyri ine, aniline, etc.) salts. By thus 11 tion of the dicarbocyanine dyes useful In practicing our ing these derivatives, they can be added to the emulsions invention is of the Order Of from to 5- P mole in substantially neutral aqueous solutions without disturb- Of Silver halide in the emulsioning the pH of the emulsions. The sulfonated derivatives useful in practicing our According to our invention, we incorporate one o mo invention can advantageously be employed in concentraof the dicarbocyanine dyes selected from those reptiOIlS 0n the Order Of from 2- P mole resented by Formula 1 above with one or more of the Of Silver halide in the emulsionsulfonated derivatives of the type described above in a Generally Speaking, the ratio of concentration of the photographic emulsion. Our invention is particularly didicarbocyanine dye to the sulfonated derivative can vary rected to the ordinarily employed gelatino-silver-halide rather widely in our combinations, e.g.,v from 1:100 to emulsions. However, our supersensitizing combinations 1:1 (by Weight) in y instancescan be employed in silver halide emulsions in which the The methods of incorporating sensitizing dyes in emulcarrier is other than gelatin, e.g., a resinous substance or sions are well known to those skilled in the art, and as cellulose material which has no deteriorating efiect on mentioned above, the sulfonated derivatives of our inthe silver halides. vention can be incorporated in the emulsions conveniently The dicarbocyanine dyes and sulfonated derivatives in substantially neutral aqueous solution. In practicing can be employed in various concentrations depending our invention, the dicarbocyanine dyes and sulfonated upon the efiects desired. As is well known in the art, the derivatives can be incorporated in the emulsions seperately or together. Frequently, it is convenient to add the dicarbocyanine dyes and sulfonated derivatives sep-- arately in the form of solutions in appropriate solvents. Methanol, ethanol, pyridine, etc., have proven satisfactory 10 tomarily employed in the art. Accordingly, the foregoing procedures and proportions are to be regarded only as illustrative. Clearly, our invention is directed to any femulsion containing a combination of the aforesaid di-- as solvents for the dicarbocyanine dyes which we emcarbocyanine dyes and sulfonated derivativeswhereby a ploy in our invention, although acetone has also been Pe ScnSitiZing effect is Obtained. found to be satisfactory in certain cases. If desired, a The following examples will serve to illustrate further mixture of solvents, such acetone and pyridine, can be the manner of practicing our invention. To diiferent por-' employed. The dicarbocyanine dyes and sulfonated detions of the same batch of photographic gelatino-silvenrivatives can be added to the emulsions in any given bromiodide emulsion were added (1) a dicarbocyanine' order, although we have found that sometimes improved dye selected from those of Formula I and (2) a comresults can be obtained if the sulfonated derivatives are bination of the dicarbocyanine dye of Formula I and a added prior to the dicarbocyanine dyes. The dicarbosulfonated derivative as defined above. Before coating, cyanine dyes and sulfonated derivatives are advantathe emulsions containing the addenda were digested forgeously incorporated in the finished, washed emulsions a short time in a tank maintained at 50-52 C. The and should be uniformly distributed throughout the diiferent portions of emulsion were then coated on sup-- emulsions. The following procedure is satisfactory: ports and exposed in the usual manner in a spectrograph. Stock solutions of the dicarbocyanine dyes and sulfonated and sensitometer (type Ib) through a Wratten 2.5 Filter, derivatives desired are prepared by dissolving the same i.e.,' a filter which transmits substantially no light of in appropriate Solvents as described abOVe- Then, to wavelengths shorter than 580 mu. The exposed coatingsthe flowable gelatino-silver-halide emulsion, the desired were than processed for a short time (3 or 4 minutes) amounts of the stock solution of one of the dicarboina developer having the following composition: cyanine dyes (or sulfonated derivatives) is slowly added, G. while stirring the emulsion. Stirring is continued until N-rnethyl-p-aminophenolsulfate 2.0- the dye is thoroughly incorporated in the emulsion. Then, Hydroquinone 8.0 the desired amount of the stock solution of the sulfonated Sodium sulfite (anhydrous) 90.0 derivative (or dicarbocyanine dye, if sulfonated deriva- Sodium carbonate (monohydrate) 52.5 tive has been added first) is slowly added to the emul- Potassium bromide 5.0 sion, while stirring. Stirring is continued until the sec- Water to make one liter.

no u rt S h 1 s H 10 d ti film fil derivatives alone are given, smce it has been found that s PPO c as g i Ce Se enva ve resm these derivatives have little or no sensitizing action on 512 3 2 to sullltable i i i i to the emulsions used. Different emulsions were used in 32 i 31 gg me are we nown to some of the examples, although the emulsions of each b d d If t d individual example were obtained from the same batch. T flmoums of i mar ocyallme yes i su 6 However, the coatings of Examples 1 to 3 were obtained denvanves actually Incorporated In emu Sum wlulvgry from the same batch of emulsion, the coatings of Exsomewhat from caseto case, according to the emu sion I amples 4 to 6 were obtained from the same batch of employed and according to the eifect deslred. The reguemulsion, and the coatings of Examples 15 to 22 were lation and adoption of the most economical and useful proportions will be apparent to those skilled in the art upon making the ordinary observations and tests cusobtained from the same batch of emulsion. The speed (red), gamma and fog for each of the coatings are given in the following table. The speed figures given in Ex- TABLE A Red Light Exposure Example Addenda (EJ111101. AgX) Speed Gamma Fog {(0) 3,3-dtethyloxathiadicarbocyanine iodide (.050) 100 3. 68 04 1 (0) dye (a) (.050) plus compound 1 (4.0) 360 5. 20 .01 dye (a) (.050) plus compound 3 (4.0) 195 4. 06 (d) dye (a) (.050) plus compound 6 (4.0) 905 4.10 .05 dye (a) (.050) 4.20 .05 dye (a) (.050) plus compound 2 (4.0) 720 4.10 06 dye (a) (.050) plus compound 4 (4.0 225 4.50 .08 dye (a) .050) plus compound 5 (4.0 230 5. 70 00 dye (a) (.050) 100 5.3 .06 dye (a) (.050) plus compound 24 (4.0) 350 5. 5 07 dye (a) (.050)- 100 4.2 .06 (I) dye (a) (.050) plus compound 18 (4.0) 295 5. 4 .06 {(m) dye (a) (.050) 100 4. 7 .07 (n) dye (a) (.050) plus compound 19 (4.0) 235 6.0 .05 (0) 3,3'-di-B-hydroxyethylthiadicarbocyamne bromide (.050) 3. 5 .66 .05 (p) dye (o) (.050) plus compound 5 (6. 4. 7 .88 .06 (q) 3,3diethyithiadicarbocyanine iodide (045)-- 5.4 2.1 .05 {(r) dye (q) (.045) plus compound 15 (1.0) 90.5 2. 7 .06 {(s) 3,3-diethylselenadicarbocyanine iodide (.045) 2. 7 2. 9 06 (i) dye (s) (.045) plus compound 15 (1.0) 50.0 2.6 .06 {(11) 3,3-diethyl-4,5,4',5'-dibenzothiadioarbocyanine iodide (.045) 5. 6 3. 1 10 (v) dye. (u) (.045) plus compound 15 (1.0) 41. 5 2. 9 .07 ((w) 3,3-diethyloxadiearbocyenine iodide (045).- 7. 6 3.2 .07 \(z) dye (w) (.045) plus compound 15 (1.0) 50.0 2. 6 .08 1) dye (a) (.050) 3.1 .92 .05 1(2) dye (a) (.050) plus compound 7 (1.0).- 16.5 1.9 .06 (a) dye (a) (.050) pins compound 8 (1.0) 15.0 1.9 06 (b) dye (a) (.050) plus compound 9 (1 7. 7 1. 8 .07 (c') dye (a) (.050) plus compound 10 12. 5 2. 1 .06 (d') dye (a) (.050) plus compound 11 (l 10. 2 1.9 .06 (e) dye (a) (.050) plus compound 12 (1 9.0 1.8 .07 (f) dye (a) (.050) plus compound 13 13. 7 2.1 .06 (a) dye (a) (.050) plus compound 14 6.2 1. 7 .06 (11' dye (a) (.045) 5. 2 1. s .05 {(i) dye (a) (.045) plus compound 25 28. 5 2.8 06 re") dye (a) (.045 5. 4 1.8 .06 \(k) dye (a) (.045) plus compound 26 (1.0) 15. 4 2.0 .06.

amples 1 to 9 are relative, while the figures given in Examples 10 to 24 are 30/ E speeds, where E is the exposure in meter candles seconds required to give a density of 0.2 above fog.

The accompanying drawing illustrates the supersensitizing efiect obtained with three of our new supersensitizing combinations in gelatino-silver-bromiodide emulsions. Each figure in the drawing is a diagrammatic reproduction of two spectrograms. In each figure, the sensitivity of the emulsion containing a dicarbocyanine dye is represented by the solid lower curve. The sensitivity of the emulsion containing the dicarbocyanine dye and a sulfonated derivative of the type described above is represented by the curve consisting of dotted lines. No curves showing the sensitivity of the emulsion containing the sulfonated derivative alone are shown, since it has been found that these sulfonated derivatives do not generally have any appreciable sensitizing action of their own when incorporated in photographic emulsions.

In Figure 1, curve A represents the sensitivity of an ordinary gelatino-silver-bromiodide emulsion sensitized with 3,3'-diethyloxathiadicarbocyanine iodide, while curve B represents the sensitivity of the same emulsion containing 3,3-diethyloxathiadicarbocyanine iodide and 3,7 bis(p tolylamido) 2,8 disulfodibenzothiophene 5,5-dioxide sodium salt. The sensitometric measurements for these emulsions are given in Example 15 of Table A.

In Figure 2, curve C represents the sensitivity of an ordinary gelatino-silver-bromiodide emulsion sensitized with 3,3'-diethyloxathiadicarbocyanine iodide, while curve D represents the sensitivity of the same emulsion sensitized with 3,3'-diethyloxathiadicarbocyanine iodide and 3,7-bis(4-methyl-Z-methoxybenzamido) -2,8-disulfodibenzothiophene-5,5-dioxide sodium salt. The sensitometric measurements for these emulsions are given in Example 16 of Table A.

In Figure 3, curve E represents the sensitivity of an ordinary gelatino-silver-bromiodide emulsion sensitized with 3,3'-diethylthiadicarbocyanine iodide, while curve F represents the sensitivity of the same emulsion sensitized with 3,3-diethylthiadicarbocyanine and and 3-[4-(4- methoxy 3 sulfobenzamido)phenyll 7 (4 methoxy 3 sulfobenzamido) dibenzothiophene 5,5 dioxide sodium salt. The sensitometric measurements for these emulsions are given in Example 11 of Table A.

Our invention is primarily directed to the ordinarily employed gelatino-silver-halide developing-out emulsions,

e.g., gelatino-silver-ehloride, -chlorobromide, -chloroiodide, -chlorobromiodide, -bromide and -bromiodide developing-out emulsions. While the results in the above table were obtained using gelatino-silver-bromiodide emulsions, excellent results have also been obtained using gelatino-silver-chlorobromide emulsions. Emulsions which form the latent image mostly inside the silver halide grains, such as the emulsions set forth in U.S. Patent 2,456,956, dated December 21, 1948, can also be employed in practicing our invention.

The emulsions prepared in accordance with our invention can be coated in the usual manner on any suitable support, e.g., glass, cellulose nitrate film, cellulose acetate film, polyvinylacetal res-in film, paper or metal.

Photographic silver halide emulsions, such as those listed above, containing the supersensitizing combinations of our invention can also contain such addenda as chemical sensitizers, e.g., sulfur sensitizers (e.g., allyl thiocarbamide, thiourea, allylisothiocyan-ate, cystine, etc.), various gold compounds (e.g., potassium chloroaurate, auric trichloride, etc.) (see U.S. Patents 2,540,085; 2,597,856 and 2,597,915), various palladium compounds, such as palladium chloride (U.S. 2,540,086), potassium chloropalladate (U.S. 2,598,079), etc., or mixtures of such sens-itizers; anti-foggants, such as ammonium chloroplatinate (U.S. 2,566,245), ammonium chloroplatinite (U.S. 2,566,263), benzotriazole, nitrobenzimidazole,

nitroindazole, benzidine, mercaptans, etc. (see Mees-- The Theory of the Photographic Process, Macmillan Pub., 1942, page 460), or mixtures thereof; hardeners, such as formaldehyde (U.S. 1,763,533), chrome alum (U.S. 1,763,533), glyoxal (U.S. 1,870,354), dibromacrolein (Br. 406,750), etc.; color couplers, such as those described in U.S. Patent 2,423,730, Spence and Carroll U.S. Patent 2,640,776, issued June 2, 1953, etc.; or mixtures of such addenda. Dispersing agents for color couplers, such as those set forth in U.S. Patents 2,322,027 and 2,304,940, can also be employed in the above-described emulsions.

As mentioned above, the supersensitizing combinations of our invention can be employed in emulsions intended for color photography, wherein color-forming compounds are incorporated in the photographic emulsions. It is known that many color-forming compounds of the type normally employed in photographic emulsions cause desensitizing and/or un-sensitizing effects. These efiects appear to be particularly troublesome with respect to colorforming compounds for the magenta or cyan images. However, we have found that the sulfonated derivatives employed in our invention are quite useful in overcoming the de-sensitizing and/or un-sensitizing caused by these color-forming compounds. Typical color-forming compounds which can be employed advantageously in combination with the super-sensitizing combinations of our invention include those in U.S. Patent 2,322,027 mentioned above and the following:

Coupler:

(1) 1 hydroxy 2 [6 (2',4' di tert.amylphenoxy)-n-butyl]-naphthamide (U.S. Patent 2,474,293)

(2) 1 hydroxy 4 phenylazo 4' (p tert. butylphenoxy) 2 naphthanilide (U.S. Patent 2,521,908)

(3) (2,4 di -tert.amylphenoxyacetamino) 4 6-dichloro-5-methyl phenol (U.S. Patent 2,725,- 291) (4) 2 (a 2,4 di tert.amylphenoxy n butyrylamino) -4,6-dichloro-5-methyl phenol (5) 6 {a {4 [a (2,4 di tert.amylphenoxy) buty-ramido] phenoxy}acetamido} 2,4 dichloro-3-methyl phenol (6) 2 [3 (2",4 diamylphenoxy) acetamido]-benzamido-4-chloro-5-methyl phenol (7) 1 (2',4',6' trichlorophenyl) 3 [3" (2",

4" di tert.amylphenoxyacetamido) benzamidol-S-pyrazolone (U.S. Patent 2,600,788)

(8) 1 (2',4,6' trichlorophenyl) 3 [3" (2",

4 di tert.amylphenoxyacetamido) benzamido] -4-(p-methoxyphenylazo -5-pyrazolone (9) N (4 benzoylacetaminobenzenesulfonyl) N-(q-phenylpropyl)-p-toluidine (U.S. Patent 2,298,443)

(10) u o Methoxybenzoyl a chloro 4 [a (2,4 di tert.amylphenoxy) n =butyram-ido] acetanilide (McCrossen U.S. application Serial No. 295,806, now U.S. Patent No. 2,728,658, dated December 27, 1955.

(11) 0c {3 [a (2,4 di tert.amylphenoxy) acetamido] -benzoyl}-2-methoxyacet-anilide (12) 3 benzoylacetamido 4 methoxy 2',4 di

tert.amylphenoxy acetanilide (13) 4 benzoylacetamido 3 methoxy 2',4' di tert.amylphenoxy acetanilide The following examples will serve to illustrate the beneficial efiects of our new supersensitizing combinations when employed in multilayer photographic emulsion layers containing incorporated color-forming compounds in the emulsions.

A photographic gelatino-silver-chlorobromide emulsion containing a coupler dispersion of a color-forming compound, such as coupler No. 5 above, was sensitized with dye (a) of Table A (.075 g./mol. AgX). To one portion of such sensitized emulsion was added a sulfonated derivative in the concentration indicated in the following table, while none was added to the remainder. In order to measure the beneficial effect of the sulfo-nated derivatives, a series of each portion of these emulsions was held at 40 C. for 30 minutes and 60 minutes, respectively, while anodier series was coated fresh holding) on a baryta-coated paper support. The other series of coatings which had been held for 30 minutes and 60 minutes, were then coated on baryta-coated paper supports. The coatings were then exposed in the usual manner and color-developed in a developer having the following composition:

Water (70-75 F.) cc 80 Sodium hexametaphosphate ....g 2.0 Sodium sulfite (anhydrous) g 4.0 Developer 1 g 3.0 Sodium carbonate (monohydrate) g 20.0 Potassium bromide ..g 2.0

Water to make one liter.

1 2-amlno-5-diethylan1lnotoluene hydrochloride.

In a manner similar to that illustrated in the above table, other sulfonated derivatives of our invention can be used to advantage in combination with dicarbocyanine dyes in photographic emulsions which contain colorforming compounds.

Methods of preparing sulfonated polycyclic compounds are well known and have been previously described in the prior art. See, for example, U.S. Patent 2,004,546, U.S. Patent 2,401,428 and U.S. Patent 2,470,629. The following examples will serve to illustrate further the method of preparing these sulfonated polycyclic compounds.

Example A.-3-(4-sulfophenyl) -7-sulfodibenzothiophenedioxide sodium salt and 4',4",2-trisulfo-p-terphenyl Hozm SQsH

SOaH

WITH CHLOROSULFONIC ACID 4,4'-diphenylbenzene, 40 g., was added to 200 ml. of chlorosulfonic acid. This addition was conducted slowly because of the vigorous evolution of hydrogen chloride. When the addition was complete, the mixture was heated on the steam bath at -90 C. for one hour. Complete solution ensued. The mixture was cooled and poured onto ice to precipitate the acid chloride which was filtered oli and dissolved in dilute sodium hydroxide. The insoluble material was filtered off, and the filtrate was evaporated to dryness. The residue was extracted for 24 hours with methanol in a Soxlet extractor to give 23 g. of sodium p-terphenyl-4',4",2-tiisulfonate (compound 21). The residue from the extraction (57 g.) was taken up in 1200 ml. of hot water and filtered. The clear blue fluorescent filtrate was treated with a hot, saturated salt solution and cooled to give 31 g. of 3-(4sulfophenyl)-7- sulfodibenzothiophene dioxide sodium salt (compound 5 Analysis for C H O Na S +H O.-Calcd.: C, H, 2.0. Found: C, 42.0; H, 2.0.

A solution containing 10 g. of 3-(4-sulfophenyl)-7- snlfodibenzothiophenedioxide sodium salt in ml. of hot water was treated with decolorizing charcoal and filtered. The filtrate was then added to a solution of 10 g.

WITH 20 PERCENT OLEUM p-Terphenyl (40 g.) was treated with 20 percent oleum all at once. The temperature rose to 100 C. Stirring and heating on the water bath was continued for 3 hours, after which time the reaction mixture had solidified. After cooling, the mixture was added to 200 ml. of water, cooled, and filtered through a sintered glass funnel. The filter cake dissolved in 1200 ml. of water and made alkaline with caustic, chilled, and the precipitated sodium salt filtered off. The sodium salt was redissolved in 2 liters of water, filtered through decolorizing carbon, and saturated salt solution was added to give 26 g. of pure 3-(4-sulfophenyl)-7-sulfodibenzothiophene dioxide sodium salt.

In a manner similar to that illustrated in the above example m-terphenyl (20 g.) gave 23 g. of 5,9-disulfo- 7,l2-dithiaindeno[1,2-a]fluorene-7,l2-bisdioxide sodium salt (compound 20). The di-o-toluidine salt of compound 20 (as monohydrate) had a melting point in excess of 274 C.

Analysis.Calcd.: C, 51.4; H, 3.8; S, 17.1; N, 3.8. Found: C, 50.9; H, 4.0; S, 16.0; N, 4.0.

In a manner similar to that illustrated in Example A above, 10 g. of p-quaterphenyl gave 8 g. of 3-(4-sulfobiphenylyl)-7-sulfodibenzothiophene dioxide sodium salt (compound 6). The di-o-tolylguanidine salt melted at C. upon recrystallization from butanol.

Analysis.-Calcd.: C, 65.0; H, 4.0. Found: C, 64.8; H, 5.0.

Compound 6 was also prepared as follows:

p-Terphenyl (10 g.) was heated with 50 ml. of concentrated sulfuric acid at 200-210 C. for 15 minutes with good stirring. Complete solution ensued. After standing overnight, the precipitate was filtered 05 through a sintered glass funnel. The solid was taken up in water and made alkaline with caustic. The sodium salt separated. Yield, 9.1 g.

Compounds 25 and 26 were prepared by condensing the appropriate o-alkoxybenzoyl chloride with 4',4"-diamino-p-terphenyl, followed by sulfonation with chlorosulfonic acid. No ring closure producing a dibenzothiophene dioxide compound was noted, although sulfonation of the corresponding p-alkoxyl derivatives did produce substantial quantities of dibenzothiophene dioxide compounds. In reactions producing a mixture of sulfonated derivatives, it is not necessary to separate the same into the component compounds, although this'can be done, if desired.

, Example B.-Pyrene-3-(4-methoxy-3-sulfostyryl)ketorie sodium salt SOsNa 1.0 g. of 3-acetylpyrene was dissolved in 35 ml. of ethanol and this solution added to a solution of 1.0 g. of sodium-3-sulfo4-anisaldehyde in 5 ml. of water, and a trace of aqueous sodium hydroxide added, whereupon a yellow color was produced. After standing overnight, the reaction mixture was filtered and the crystalline product (1.0 g) was rinsed with alcohol and dried in air.

Example C.2,3-dimethylnaphIhalene-I-sulf0rric acid sodium salt SIOaND 20 g. of 2,3-dirnethylnaphthalenc were mixed with 20 ml. of sulfuric acid, and the mixture was heated to 80 C. with stirring for 2 hours, or until the same was completely solubilized in dilute alkali. Water (100 ml.) was added and the mixture heated to boiling. Complete solution ensued on cooling. The desired acid separated as beautiful crystals from the blue fluorescent solution. The yield was 15 g. The desired sodium salt was obtained by dissolving the acid in alkali and evaporating to dryness. Either the free sulfonic acid or the sodium salt can be used to advantage in our invention.

Compound 17 was described according to the method described in Annalen," vol. 531, page 106. The preparation of compound 16 is described in Chemical Abstracts, vol. 31, page 1825. Compound 18 is described in Chemical Abstracts, vol. 35, page 4009. Other compounds selected from those represented by Formula II above are described in US. Patents 2,563,795; 2,590,632 and 2,702,759.

The term sulfo is used in the foregoing specification and in the following claims to mean the free acid group, as well as salts of this free acid group, including alkali metal salts (e.g., sodium, potassium, etc.), ammonium salts, amine addition salts (e.'g., triethylamine, ethanolamine, triethanolamine, pyridine, picolines, etc). As mentioned above, one advantage of adding the sulfonated derivatives in the form of their salt solutions is that the pH of the solution is not disturbed. However, when using small quantities of sulfonated derivatives, the free acids can also be used to advantage.

What we claim as our invention and desire secured by Letters Patent of the United States is:

l. A photographic silver halide emulsion sensitized with a supersensitizing combination of at least one dicarbocyanine dye selected from those represented by the following general formula:

, those of the naphthoselenazole series, those of the benzoxazole series, those of the naphthoxazole series, those of the Z-quinoline series, those of the 4-quinoline series, those of the benzirnidazole series, and those of the 5,6-benzoquinoline series, and 2, represents the nonmetallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzoxazole series, those of the naphthoxazole series, those of the benzoselenazole series, those of the naphthoselenazole series, those of the benzothiazole series, and those of the naphthothiazole series, and at least one aromatic compound, containing at least one sulfo group, selected from the class consisting of (a) a carbocyclic compound selected from those represented by the following general formula:

wherein D represents an aromatic group comprising an aromatic ring selected from the class consisting of a biphenyl ring, a terphenyl ring, and an aromatic group containing at least 2 benzene rings fused together, (b) a water-soluble salt of a compound represented by said Formula 2, and (c) a dibeuzothiophene dioxide compound selected from those represented by the following general formula:

iii-R1 x wherein R and R each represents an alkyl group contain- I ing from 1 to 4 carbon atoms, n represents a positive integer of from 1 to 2, X represents an acid radical, Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the benzoselenazole series, those of the naphthoselenazole series, those of the benzoxazole series, those of the naphthoxazole series, those of the Z-quinoline series, those of the 4-quinoline series, those of the benzimidazole series, and those of the 5,6-benzoquinoline series, and 2, represents the nonmetallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzoxazole series, those of the naphthoxazole series, those of the benzoselenazole series, those of the naphthoselenazole series, those of the benzothiazole series, and those of the naphthothiazole series, and at least one dibenzothiophene dioxide compound selected from those represented by the following general formula:

wherein R represents a member selected from the group consisting of an acylamido group and a sulfo group, R represents a member selected from the group con- 17 sisting of an acylamido group and a sulfoaryl group, and R represents a member selected from the group consisting of a hydrogen atom and a sulfo group, said dibenzothiophene dioxide compound containing at least one sulfo group.

3. A photographic gelatino-silver-halide developing-out emulsion sensitized with a supersensitizing combination of at least one dicarbocyanine dye selected from those represented by the following general formula:

wherein D represents an aromatic group comprising an aromatic ring selected from the class consisting of a biphenyl ring, a t'erphenyl ring and an aromatic group containing at least 2 benene rings fused together, (b) a water-soluble salt of a compound represented by said Formula 2, and (c) a dibenzothiophene dioxide compound selected from those represented by the following general formula:

wherein R represents a member selected from the group consisting of an acylamido group and a sulfo group, R represents a member selected from the group consisting of an acylamido group and a sulfoaryl group containing from 6 to 12 carbon atoms, and R represents a member selected from the group consisting of a hydrogen atom and a sulfo group, said dibenzothiophene dioxide compound containing at least one sulfo group.

4. A photographic gelatino-silver-halide developing-out emulsion as defined in claim 3, wherein the silver halide is silver bromiodide.

5. A photographic gelatino-silver-halide developing-out emulsion sensitized with a supersensitizing combination of at least one dicarbocyanine dye selected from those represented by the following general formula: /Z\ /Z1\\ (2) HO H wherein D represents an aromatic group comprising an aromatic ring selected from the class consisting of a biphenyl ring, a terphenylring and an aromatic group a a is it containing at least 2 benzene rings fused together, (b) a water-soluble salt of a compound represented by said Formula 2 and (c) a dibenzothiophene dioxide compound I selected from those represented by the following general formula:

wherein R represents a member selected from the group consisting of an acylamido group and a sulfo group, R represents a member selected from the group consisting of an acylamido group and a sulfoaryl group containing from 6 to 12 carbon atoms, and R represents a member selected from the group consisting of a hydrogen atom and a sulfo group, said dibenzothiophene dioxide compound containing at least one sulfo group.

6. A photographic gelatino-siliver-halide developingout emulsion sensitized with a supersensitizing combination of at least one dicarbocyanine dye selected from those represented by the following general formula:

X wherein R and R eachrepresents an alkyl group containing from 1 to 2 carbon atoms, X represents an acid radical, Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the benzothiazole series and Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the benzoxazole series, and at least one dibenzothiophene compound selected from those represented-by the following general formula:

wherein R represents a member selected from the group consisting of an acylamido group and a sulfo group, R represents a member selected from the group consisting of an acylamido group and a sulfoaryl group containing from 6 to 12 carbon atoms, and R represents a member selected from the group consisting of a hydrogen atom and a sulfo group, said dibenzothiophene dioxide compound containing at least one sulfo group.

those represented by the following general formula:

11-16 o=oH-cn=oH-o11=oH-6 I-R1 wherein R and R each represents an alkyl group containing from 1 to 2 carbon atoms, X represents an acid radical and Z and Z each represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the benzothiazole series, and at least one aromatic compound,

containing at least one sulfo group, selected from the class consisting of (a) a carbocyclic compound selected from those represented by the following general formula:

wherein D represents an aromatic group comprising an aromatic ring selected from the class consisting of a biphenyl ring, a terphenyl ring and an aromatic group containing at least 2 benzene rings fused together, (b) a water-soluble salt of a compound represented byv said Formula 2, and (c) a dibenzothiophene dioxide compound selected from those represented by the following general formula:

wherein R represents a member selected from the group consisting of an acylamido group and a sulfo group, R represents a member selected from the group consisting of an acylamido group and a sulfoaryl group containing from 6 to 12 carbon atoms, and R represents a member the benzoselenazole series, and at least one aromatic compound, containing at least one sulfo group, selected from the class consisting of (a) a carbocyclic compound selected from those represented by the following general, formula:

wherein D represents an aromatic group comprising an aromatic ring selected from the class consisting of a biphenyl ring, a terphenyl' ring and an aromatic group containing at least 2 benzene rings fused together, (b) a selected from the group consisting of a hydrogen atom taining from 1 to 2 carbon atoms, X represents an acid radical, and Z and Z each represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the benzothiazole series, and at least one dibenzothiophene compound selected from those represented by the following general formula:

methoxy 3 sulfobenzamido)phenyl] 7 (4 methoxy- 3-sulfobenzamido)dibenzothiophene dioxide sodium salt. 12. A photographic vgelatino-silver-halide developing:

out emulsion sensitized with a supersensitizing combination of at least onedicarbocyanine dye selected from those represented by the following general formula:

is-R,

wherein R and R each represents an alkyl group cons.

taining from 1 to 2 carbon atoms, X represents an acid radical and Z and Z each represents the non metallic water-soluble salt of a compound represented by said Formula 2 and (c) a dibenzothiophenedioxide compound selected from those represented by the following general formula:

wherein R represents a member selected from the group consisting of an acylamido group and a sulfo group, R represents a member selected from the group consisting of an acylamido group and a sulfoaryl group containing from 6 to 12 carbon atoms, and R represents a member selected from the group consisting of a hydrogen atom and a sulfo group, said dibenzothiophene dioxide compound containing at least one sulfo group.

13'. A photographic gelatino-silver-halide developing out emulsion sensitized with a supersensitizing combination of at least one dicarbocyanine dye selected from those represented by the following general formula:

wherein R and R each represents an alkyl group containing from 1 to 2 carbon atoms, X represents an acid radical, and Z and Z each represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the benzoselenazole series, and at least one dibenzothio phene compound selected from thoserepresented by the following general formula:

wherein R represents a member selected from the group consisting of an acylamido group and a sulfo group, R represents a member selected from the group consisting of an acylamido group and a sulfoaryl group containing from 6 to 12 carbon atoms, and R represents a member selected from the group consisting of a hydrogen atom and a sulfo group, said dibenzothiophene dioxide compound containing at least one sulfo group.

14. A photographic gelatino-silver-halide developingout emulsion sensitized with a supersensitizing combina tion of 3,3'-diethylselenadicarbocyanine iodide and 3-[4 (4 methoxy 3-sulfobenzamido)phenyl] 7 (4 methoxy-3-sulfobenzamido)dibenzothiophene dioxide sodium salt.

15. A photographic gelatino-silver-halide developingtion of at least one dicarbocyanine-dye selectedfrom thoserepresented by the following general formula:

wherein R and R each represents an -,alkyl -group; con

radical and Z and Z each represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the naphthothiazole series, and at least one aromatic compound, containing at least one sulfo group, selected from the class consisting of (a) a carbocyclic compound selected from those represented by the following general formula:

(2) DSO H wherein D represents an aromatic group comprising an aromatic ring selected from the class consisting of a biphenyl ring, a terphenyl ring and an aromatic group containing at least 2 benzene rings fused together, (b) a water-soluble salt of a compound represented by said Formula 2, and (c) a dibenzothiophene dioxide compound selected from those represented by the following general formula:

wherein R and R each represents an alkyl group containing from 1 to 2 carbon atoms, X represents an acid radical, and Z and Z each represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the naphthothiazole series, and at least one dibenzothiophene compound selected from those represented by the following general formula:

wherein R represents a member selected from the group consisting of an acylamido group and a sulfo group, R represents a member selected from the group consisting of an acylamido group and a sulfoaryl group containing from 6 to 12 carbon atoms, and R represents a member selected from the group consisting of a hydrogen atom and a sulfo group, said dibenzothiophene dioxide compound containing at least one sulfo group.

17. A photographic gelatino-silver-halide developingout emulsion sensitized with a supersensitizing combination of 3,3'-diethyl-4,5,4',5'-dibenzothiadicarbocyanine iodide and 3-[4-(4-methoxy-3-sulfobenzamido)phenyl]-7- (4 methoxy 3 sulfobenzamido)dibenzothiophene dioxide sodium salt.

18. A photographic silver halide emulsion capable of producing a cyan dye image comprising a silver halide emulsion containing a dispersion of a color-forming phenolic compound capable of reacting with a primary aromatic amine developing agent, and at least one dicarbocyanine dye selected from those represented by the following general formula:

wherein R and R each represents an alkyl group containing from 1 to 4 carbon atoms, n represents a positive integer of from 1 to 2, X represents an acid radical, Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the benzoselenazole series, those of the naphthoselenazole series, those of the benzoxazole series, those of the naphthoxazole series, those of the 2-quinoline series, those of the 4-quinoline series, those of the benzimidazole series, and those of the 5,6-benzoquinoline series, and Z represents the nonmetallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzoxazole series, those of the naphthoxazole series, those of the benzoselenazole series, those of the naphthoselenazole series, those of the benzothiazole series, and those of the naphthothiazole series, and at least one aromatic compound, containing at least one sulfo group, selected from the class consisting of (a) a carbocyclic compound selected from those represented by the following general formula:

(2) DSO H wherein D represents an aromatic group comprising an aromatic ring selected from the class consisting of a biphenyl ring, a terphenyl ring, and an aromatic group containing at least 2 benzene rings fused together, (b) a water-soluble salt of a compound represented by said Formula 2, and (c) a dibenzothiophene dioxide compound selected from those represented by the following general formula:

wherein R represents a member selected from the group consisting of an acylamido group and a sulfo group, R represents a member selected from the group consisting of an acylamido group and a sulfoaryl group, and R represents a member selected from the group consisting of a hydrogen atom and a sulfo group, said dibenzothiophene dioxide compound containing at least one sulfo group.

References Cited in the file of this patent UNITED STATES PATENTS 2,186,717 Eggert et al. Ian. 9, 1940 2,412,815 Kendall et al Dec. 17, 1946 2,534,050 Murray Dec. 12, 1950 2,701,197 Thirtle et al. Feb. 1, 1955 2,725,292 Graham et al Nov. 29, 1955 2,759,816 Minsk Aug. 21, 1956 2,848,329 Chechak et al. Aug. 19, 1958 FOREIGN PATENTS 484,289 Canada June 24, 1952 UNITED STATES PATENT OFFICE Certificate of Correction Patent No. 2,937,089 May 17, 1960 Jean E. Jones et al.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, lines 59 and 60, the left-hand portion of the formula should appear as shown below instead of as in the patent:

R-N E CII==-OH)u-1 "1: column 4, lines 15 to 19, the right-hand portion of the formula should appear as shown below instead of as in the patent:

column 12, line 37, Coupler (3), for that portion reading -2,4:-diread 2-(2,4-di-; column 21, lines 19 to 23, the right-hand portion 0 the formula should appear as shown below instead of as in the patent:

line 27, for a sulfoaryl groups read -a sulfoaryl group-. Signed and sealed this 29th day of November 1960.

Attest:

KARL H. AXLINE, ROBERT C. WATSON, Attestz'ng Oficer. Commissioner of Patents. 

18. A PHOTOGRAPHIC SILVER HALIDE EMULSION CAPABLE OF PRODUCING A CYAN DYE IMAGE COMPRISING A SILVER HALIDE EMULSION CONTAINING A DISPERATION OF A COLOR-FORMING PHENOLIC COMPOUND CAPABLE OF REACTING WITH A PRIMARY AROMATIC AMINE DEVELOPING AGENT, AND AT LEAST ONE DICARBOCYANINE DYE SELECTED FROM THOSE REPRESENTED BY THE FOLLOWING GENERAL FORMULA: 